Hearing Aid System and Method for Operating a Hearing Aid System

Description

[0001] The invention relates to a hearing aid system. The invention also relates to a method for operating such a hearing aid system.

[0002] Hearing devices are typically used to output an audio signal to the wearer's ear. This output is achieved via an output transducer, usually acoustically through sound waves transmitted via a loudspeaker (also called a "receiver"). Such hearing devices are frequently used as assistive listening devices (or simply hearing aids). They typically include an acoustic input transducer (especially a microphone) and a signal processor. This processor is designed to process the input signal (also called the microphone signal) generated from the ambient sound by the input transducer, using at least one user-specific signal processing algorithm, in such a way as to at least partially compensate for the wearer's hearing loss.Particularly in the case of a hearing aid, the output transducer can be a loudspeaker, a bone conduction receiver, or a cochlear implant, all of which are designed to mechanically or electrically couple the sound signal into the wearer's ear. The term "hearing devices" also includes devices such as tinnitus maskers, headsets, headphones, and similar devices.

[0003] Similar to the increasing use of features in so-called "wearables," such as fitness trackers, smartwatches, and the like, which use sensors to record bodily functions (e.g., pulse, movement, etc.), the use of such functions is also becoming more common in hearing aids. For example, body temperature, pulse, or similar data may be recorded. Such an additional use of hearing aids is particularly advantageous because, especially in the case of hearing aids, these devices are usually worn close to the body and often for relatively long periods or even continuously.

[0004] US Patent 2019 / 0253793 A1 discloses an in-the-ear hearing aid. The device contains at least one electroacoustic transducer and at least one sensor or at least one active electronic component. The at least one electroacoustic transducer comprises a capsule that encloses a sound-active part of the transducer and an air volume of the transducer. The transducer air volume is an air volume enclosed by the capsule and in fluid communication with the sound-active part of the transducer. At least a portion of the at least one sensor or the at least one active electronic component is located within the transducer air volume.

[0005] US 2020 / 0025732 A1 describes the use of sensors on earbuds and / or headphones to monitor the biometric data of a user and / or the environment.

[0006] WO 2019 / 232042 A1 describes a biometric sensor head assembly. This assembly comprises a body element with an internal opening. An optical source is attached to the body element at a first location, and an optical detector is attached to the body element at a second location. An audio driver is attached to the body element. An ear gel, designed to be inserted into an ear canal, is attached to the body element, and at least part of it is transparent to one or more wavelengths of light. A first optical fiber is attached to an inner surface of the ear gel via a corresponding first end, and a second optical fiber is attached to the inner surface of the ear gel via a corresponding first end. A second end of the first optical fiber is in optical communication with the optical source, and a second end of the second optical fiber is in optical communication with the optical detector.

[0007] The invention is based on the objective of improving the detection of bodily functions using a hearing device.

[0008] This problem is solved according to the invention by a hearing device having the features of claim 1. Furthermore, this problem is solved according to the invention by a method having the features of claim 9. Advantageous and partly inventive embodiments and further developments of the invention are set out in the dependent claims and the following description.

[0009] The hearing aid system according to the invention comprises a photoplethysmography sensor which, in its intended wearing state, is to be worn in the ear canal of the person using the hearing aid system. Furthermore, the hearing aid system comprises an earpiece which, in its intended wearing state, at least partially covers the photoplethysmography sensor towards the ear canal. In particular, the earpiece serves to hold the photoplethysmography sensor, at least indirectly, in its intended wearing position in the ear canal. The hearing aid system also comprises a controller which is configured to derive, from light detected (and preferably also emitted) by the photoplethysmography sensor, a reference value characteristic of the transmission of the earpiece for a wavelength range used by the photoplethysmography sensor.Furthermore, the controller is configured to compare the reference variable with a predefined first limit value and, if the limit value is exceeded by the reference variable, to issue a warning message.

[0010] According to the inventive method, for the operation of the hearing device described above – which comprises the photoplethysmography sensor to be worn in the ear canal in the intended wearing state and the earpiece which, in the intended wearing state, at least partially covers the photoplethysmography sensor towards the ear canal – the reference value for the transmission of the earpiece is derived for a wavelength range of the photoplethysmography sensor based on the light detected by the photoplethysmography sensor, the reference value is compared with a predetermined first limit value, and if the limit value is exceeded by the reference value, a warning message is issued.

[0011] The hearing aid system, specifically its controller, is thus configured to execute the method according to the invention, in particular automatically. Conversely, the method comprises all measures performed by the controller as described here and below. Therefore, the hearing aid system and the method share the features (especially those relating to the process) and the resulting advantages described here and below in a corresponding manner.

[0012] In this context, and in the following, "characteristic" means that the reference quantity contains quantitative information about the magnitude of the transmission, such that the transmission can at least be communicatively read from the reference quantity. For example, the reference quantity indicates the transmission itself (especially the transmission across the entire transmission path of the light in the photoplethysmography sensor) or, alternatively, the absorption complementary to the transmission. The reference quantity can also be a quantity that is directly or indirectly proportional to the transmission to be displayed. Furthermore, the reference quantity can also have a non-linear relationship with the transmission to be displayed, for example, a logarithmic, exponential, or polynomial (i.e., quadratic, cubic, etc.) relationship.

[0013] The term "limit value exceedance" (here, exceeding the first limit value) is preferably always to be understood here and in the following as direction-independent, in the sense that the difference between the reference quantity (or its change over time) and the limit value changes sign. Depending on the definition of the reference quantity ("true" transmission or absorption), exceeding the respective limit value can therefore be positive (in the sense of a true exceedance, where the reference quantity becomes greater than the limit value) or negative (in the sense of a fall below the limit value, where the reference quantity becomes less than the limit value). Thus, the warning message is issued, in particular, when the reference quantity reflects absorption and becomes greater than the first limit value. Conversely, the warning message is preferably issued when the reference quantity reflects transmission and falls below the first limit value.

[0014] Since the measurement principle of the photoplethysmography sensor is based on irradiating body tissue with light from one or more predefined wavelength ranges (e.g., different bands of the near-infrared and / or visible wavelength ranges) and recording reflected or transmitted radiation to determine tissue properties, particularly current blood flow, the transmission of the earpiece obviously influences the evaluation and determination of these tissue properties. Therefore, the first limit value described above is preferably chosen (predefined) such that a sufficient amount of light is still received for the evaluation and determination of tissue properties. In other words, the first limit value preferably indicates the threshold beyond which a reliable evaluation and determination of tissue properties is no longer possible.Thus, by determining and comparing the reference value with the first limit value, it is advantageous to inform the users of the hearing aid system that the function of the photoplethysmography sensor is limited.

[0015] The controller is further configured to compare the reference value not only with the first but also with a second reference value, and, depending on the position of the reference value relative to the second reference value, to infer a first type, in particular a first color type, of the earpiece. This is especially useful because hearing aids often come with earpieces in different colors (i.e., different color types). However, not all colorations—even if the earpiece remains translucent—are suitable for the reliable (i.e., sufficiently accurate) use of the photoplethysmography sensor, as at least a significant proportion of light is absorbed.

[0016] In In a further development of the aforementioned design, the controller is configured to compare the reference value with a third limit value. In this case, the first limit value lies between the second and third limits. The controller is specifically configured to determine a second type, particularly a second color type, of earpiece based on the position of the reference value relative to the third limit value. Specifically, the controller is configured to distinguish between a color type with sufficiently high transmission and one with insufficient transmission. This is particularly advantageous because hearing aids often come with different earpieces in various colors (i.e., different color types), such as light, dark, transparent, opaque, or the like.Preferably, the controller is configured to issue a recommendation for a suitable earpiece type when an earpiece type unsuitable for use with the photoplethysmography sensor is detected, in particular a color type.

[0017] For example, the second limit value (assuming that it, and therefore the reference value, reflects the transmission itself) lies above the first limit value (thus representing a higher transmission value than that set by the first limit value). In this case, the third limit value lies below the first limit value and therefore represents a transmission that is significantly too low.

[0018] Optionally, several second and / or third limit values ​​can also be specified, which can be used, for example, to differentiate between several color schemes or several earpieces from different manufacturers.

[0019] In In a suitable design, the controller is configured to use an exceedance of the first limit value by the reference value as an indication of contamination of the earpiece and to issue a warning message requesting cleaning or replacement of the earpiece.

[0020] In an advantageous combination of contamination detection with the comparison described above against the second or even the third limit value, the controller is expediently configured to infer contamination only when the first limit value is exceeded, but not the second or third. Contamination detection is advantageously possible when the transmission of the earpiece's color type, which is unsuitable for use with the photoplethysmography sensor, is so low (in other words, its absorption is so high) that the distance from the first limit value, beyond which the use of the photoplethysmography sensor is significantly affected, is such that not only such an unsuitable color type but also contamination triggers the warning message.

[0021] In a preferred embodiment, the hearing device system comprises a hearing device (in particular, a hearing aid) to which the photoplethysmography sensor is coupled. In particular, the photoplethysmography sensor is part of the hearing device. In this case, the controller is advantageously configured to determine the reference value after a change of the earpiece and / or after activation of the hearing device, and preferably also to compare it with the respective limit value(s). Optionally, the controller is configured to repeatedly determine the reference value during the ongoing operation of the hearing device and, in particular, to compare it with the respective limit value(s).

[0022] In a suitable embodiment, the first limit value, and optionally also the second and / or third limit value, is selected such that the influence of body tissue on the emitted light of the photoplethysmography sensor is taken into account. In other words, the corresponding limit value is already chosen so that the reference value is determined after irradiation of the body tissue. It is well known that body tissue causes an additional attenuation of the emitted light (beyond that caused by the earpiece). The first limit value therefore preferably indicates how much light must be detected after irradiation of the user's body for the proper, and in particular reliable, use of the photoplethysmography sensor. Similarly, the second and third limit values—if present—indicate how much light must be detected after irradiation of the body in order to assign the respective color type to the earpiece.

[0023] Preferably, the first (and especially the second and third) limit value represents the ratio of received light intensity to emitted light intensity. In particular, the first limit value is at least 65 percent at a wavelength in the range of approximately 860 (+ / - 20) nanometers.

[0024] In another practical embodiment, the hearing device comprises a main body to be worn behind the ear, which includes a signal processor and at least one microphone coupled to it. Furthermore, in this case, the hearing device includes a loudspeaker to be worn in the ear canal, which is coupled to the signal processor via signal transmission. In particular, the hearing device is a behind-the-ear hearing aid (also referred to as "BTE" for "behind the ear") with an external loudspeaker (also known as "RIC" for "receiver in canal" or "RIC-BTE"). In In this design, the loudspeaker preferably carries the photoplethysmography sensor; in particular, the latter is integrated into the loudspeaker.

[0025] In the aforementioned case of the "RIC" hearing aid, the earpiece (especially one suitable or intended for use with the photoplethysmography sensor) is preferably formed as a flexible covering for the loudspeaker and made of a transparent, and in particular, uncolored material. For example, the earpiece—also referred to as an "ear dome" in this case—is made of silicone. An earpiece not suitable for use with the photoplethysmography sensor, on the other hand, is made of a (particularly dark) colored material, especially silicone.

[0026] The controller of the hearing aid system described above is optionally designed as a non-programmable electronic circuit. Alternatively, the controller is formed by a microcontroller in which the functionality for carrying out the method according to the invention described above is implemented in the form of a software module.

[0027] In one optional configuration, the controller is integrated into the hearing aid's signal processor. Alternatively, or optionally in addition to the existing controller (e.g., to enable a more energy-efficient mode for the hearing aid), the controller is external to the hearing aid and implemented, for example, as an app (i.e., the aforementioned software module) on a smartphone. Thus, the smartphone, particularly when the app is installed, becomes part of the hearing aid system, at least during app use. In this case, the data (especially the sensor signals) from the photoplethysmography sensor are preferably transmitted wirelessly to the smartphone via a communication interface on the hearing aid.

[0028] Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. The drawing shows: Fig. 1 in a schematic representation of a hearing device system with a hearing device comprising an external loudspeaker and a photoplethysmography sensor, Fig. 2 in a schematic partial sectional view of the loudspeaker with the photoplethysmography sensor in the intended wearing state in the ear canal of a user, and Figs. 3, 4 each in schematic diagrams a comparative value determined in the intended wearing state by means of the photoplethysmography sensor for a transmission of an earpiece.

[0029] Corresponding parts and sizes are always marked with the same reference symbols in all figures.

[0030] In Fig. 1 Figure 1 shows a hearing device in the form of a hearing aid, specifically a hearing aid worn behind the ear by a user (referred to here as "BTE 1"). The BTE 1 comprises a housing 2 in which electronic components of the BTE 1 are arranged. These electronic components include, for example, two microphones 4, a signal processor 6, and a battery module 8. In the intended operation of the BTE 1, the microphones 4 serve to receive ambient sound and convert it into electrical input signals (also called "microphone signals MS"), which are processed by the signal processor 6 (also called "controller") (in particular, filtered, frequency-dependently amplified, and / or attenuated, etc.).The processed input signals are then output as output signals AS to a loudspeaker 10, which is arranged externally to the housing 2 and is intended to be worn in the ear canal 9, and are converted by this into sound signals and passed on to the user's ear.

[0031] The BTE 1 also features a photoplethysmography sensor, or "PPG sensor 12" for short, which in the present embodiment is integrated into the loudspeaker 10, specifically into its housing 14 (see figure). Fig. 2 The PPG sensor 12 is used to determine, for example, the pulse, and optionally also the oxygen saturation, of the user of the BTE 1. For this purpose, the PPG sensor 12 includes a light source, in this case an LED unit 16, which is configured to emit several frequency bands, but usually at least light in the near-infrared range. The PPG sensor 12 also includes a light sensor 18, which detects incident light. In normal operation, the light sensor 18 detects radiation emitted by the LED unit 16 and reflected by body tissue, for example, the wall 20 of a blood vessel 22 of the user. Based on the intensity profile recorded, the user's pulse, for example, can then be determined.

[0032] To keep the loudspeaker 10 in the ear canal 9, the BTE 1 is also equipped with an earpiece, specifically a mushroom-shaped and flexible covering called "dome 24" (or "sleeve"). This dome 24 covers, as shown in Fig. 1 und 2 The PPG sensor 12 is at least partially visible. Due to the absorption inherent in the material of the dome 24 (i.e., a transmission of less than 100 percent), the light is already attenuated on its path between the LED unit 16 and the light sensor 18. This attenuation is more or less pronounced depending on the color of the dome 24. Different colored domes 24 are typically available for the BTE 1, usually an uncolored and a dark version.

[0033] The BTE 1, together with the currently applied dome 24, also forms a "hearing device system".

[0034] However, for proper use, specifically for reliable results from the PPG sensor 12, a predetermined intensity value, which is received at a minimum by the light sensor 18, is required. The signal processor 6 is therefore configured to determine a reference value, characteristic of the dome 24's transmission, based on the detected light (optionally for each emitted wavelength band or, by way of example, for one band). This reference value—referred to here as the "actual transmission value TI"—is determined as the ratio between the detected light intensity and the intensity emitted by the LED unit 16. This actual transmission value TI thus includes, as is recognized, both the attenuation by the dome 24 and by the user's body tissue. Fig. 3 Figure 1 shows a diagram in which the transmission T is plotted against the wavelength λ. The progression of the actual transmission value TI across the measured wavelength bands is shown as an example.

[0035] The signal processor 6 then compares the actual transmission value TI with a predefined first limit value G1 (see below). Fig. 3 This first limit value G1 is chosen such that below it, reliable function of the PPG sensor 12 is not guaranteed, i.e., the attenuation (absorption) by the dome 24 and the body tissue is too high. If the actual transmission value TI is as described in Fig. 3 As shown, above the first limit value G1, the signal processor 6 continues its intended operation. If the actual transmission value TI falls below the limit value G1, the signal processor 6 issues a warning message.

[0036] To further specify the warning message, in another embodiment, a second limit value G2 and a third limit value G3 are stored in the signal processor 6. The second limit value G2 is above and the third limit value G3 is below the first limit value G1.

[0037] This allows the signal processor 6 to distinguish between different types, specifically different colors, in this case a light or colorless color and a dark color, of the dome 24. If the transmission value falls below a certain threshold... TI Based on the first and third limit values ​​G1 and G3, signal processor 6 concludes that the dark-colored version of dome 24 is installed. Signal processor 6 then issues a warning message instructing the user to install the uncolored version of dome 24.

[0038] If the actual transmission value exceeds TI Based on the second limit value G2, the signal processor 6 concludes that the uncolored version of the dome 24 is installed.

[0039] In the event that the transmission value TI If the first limit value G1 is undershot, but not the third limit value G3, the signal processor 6 concludes in a further embodiment that the dome 24 is dirty, e.g. because cerumen has accumulated on the dome 24. In In this case, the signal processor 6 issues a warning message recommending that the dome 24 be cleaned or replaced.

[0040] In In an embodiment not shown in detail, the aforementioned hearing aid system also includes a smartphone on which a software application is implemented, which is configured and designed to evaluate the data from the PPG sensor 12. In this embodiment, this application is also configured and designed to perform the "monitoring" of the transmission of the dome 24 carried out above by the signal processor 6. In In this case, the smartphone, specifically its microprocessor in conjunction with the application, acts as a controller that determines the actual transmission value TI and compares it with the first limit value G1 and, if applicable, also with the second and third limit values ​​G2 and G3, and, if necessary, issues a warning message. The BTE 1 in this case has a wireless interface through which the data from the PPG sensor 12 is transmitted to the smartphone. Reference symbol list

[0041] 1BTE 2Housing 4Microphone 6Signal processor 8Battery module 9Aural canal 10Speaker 12PPG sensor 14Housing 16LED unit 18Light sensor 20Vessel wall 22Blood vessel 24Dome MS Microphone signal AS Output signal T Transmission TI Actual transmission value G1 First limit value G2 Second limit value G3 Third limit value λ Wavelength

Claims

1. Hearing device system, having - a photoplethysmography sensor (12) to be worn in the auditory canal in an intended worn state, - an earpiece (24) which at least partly covers the photoplethysmography sensor (12) toward the auditory canal (9) in the intended worn state, and - a controller (6), characterized in that the controller (6) is configured to use light captured by the photoplethysmography sensor (12) to derive a comparison quantity (TI) of the earpiece (24) characteristic for a transmission (T) of the earpiece (24), for a wavelength range of the photoplethysmography sensor (12), to compare the comparison quantity (TI) with a specified first limit (G1) and to output an alert if the first limit (G1) is traversed by the comparison quantity (TI), and in that the controller (6) is configured to compare the comparison quantity (TI) with a second limit (G2) and to deduce a first type, in particular a first colour type, of the earpiece (24) on the basis of a relative position of the comparison quantity (TI) in relation to the second limit (G2).

2. Hearing device system according to Claim 1, wherein the controller (6) is configured to compare the comparison quantity (TI) with a third limit (G3), the first limit (G1) being between the second and the third limit (G2, G3), and to deduce a second type, in particular a second colour type, of the earpiece (24) on the basis of a relative position of the comparison quantity (TI) in relation to the third limit (G3).

3. Hearing device system according to either one of Claims 1 and 2, wherein the controller (6) is configured to draw upon the first limit (G1) being traversed by the comparison quantity (TI) as an indication for dirtying of the earpiece (24) and to output a request to clean or renew the earpiece (24) with the alert.

4. Hearing device system according to Claim 3 and according to Claim 1 or 2, wherein the controller (6) is configured to deduce dirtying if only the first limit (G1) is traversed and not the second or third limit (G2, G3).

5. Hearing device system according to any one of Claims 1 to 4, having a hearing device (1) to which the photoplethysmography sensor (12) is coupled, wherein the controller (6) is configured to determine the comparison quantity (TI) following a replacement of the earpiece (24) and / or following the activation of the hearing device (1).

6. Hearing device system according to any one of Claims 1 to 5, wherein the first limit (G1), and optionally also the second and / or the third limit (G2, G3), is chosen such that an influence of body tissue on the light emitted by the photoplethysmography sensor (12) is taken into account.

7. Hearing device system according to any one of Claims 1 to 6, wherein the hearing device (1) has a main body that is to be worn behind the ear, said main body comprising a signal processor (6) and at least one microphone (4) coupled therewith, and a loudspeaker (10) which is to be worn in the auditory canal (9) and coupled to the signal processor (6) for signal transmission purposes, the loudspeaker (10) carrying the photoplethysmography sensor (12).

8. Hearing device system according to Claim 7, wherein the earpiece (24) is designed as a flexible cover for the loudspeaker (10) and is formed from transparent, more particularly non-coloured material.

9. Method for operating a hearing device system which has a photoplethysmography sensor (12) to be worn in the auditory canal (9) in an intended worn state and an earpiece (24) which covers the photoplethysmography sensor (12) toward the auditory canal (9) in the intended worn state, characterized in that according to the method - light captured by the photoplethysmography sensor (12) is used to derive a comparison quantity (TI) characteristic for a transmission (T) of the earpiece (24), for a wavelength range of the photoplethysmography sensor (12), - the comparison quantity (TI) is compared with a specified first limit (G1), - an alert is output if the first limit (G1) is traversed by the comparison quantity (TI), and - the comparison quantity (TI) is compared with a second limit (G2) and a first type, in particular a first colour type, of the earpiece (24) is deduced on the basis of a relative position of the comparison quantity (TI) in relation to the second limit (G2).